While he yet spoke, behold, a bright cloud overshadowed them: and behold a voice out of the cloud, which said, This is my beloved Son, in whom I am well pleased; hear you him. Mat 17:5 But the Lord (Holy Spirit) had a simple command: hear my Son Jesus.      Calling on the Lord is futile because the Lord is just the generic name for deity.     The Holy Spirit has ordained all power in heaven and earth be under the name of Jesus.

And there was a cloud that overshadowed them: and a voice came out of the cloud, saying, This is my beloved Son: hear him. Mar 9:7 The Holy Spirit is very succinct: Jesus is my Son.     Listen to what He says.

And there came a voice out of the cloud, saying, This is my beloved Son: hear him. Luk 9:35 The Holy Spirit Himself tells Peter what to do - listen to My Son, Jesus.